Summary
The 1977 BMW 3 Series has 6 recalls, the most serious being multiple throttle defects that can prevent the accelerator from returning to idle after the driver releases the pedal, leaving the engine running at elevated speed.
Several separate issues contribute to this throttle problem. Rubber damping sleeves on the throttle return springs can shrink in hot weather and bind the springs, while in extreme cold the protective sleeve on the throttle cable can stiffen and have the same effect. The return springs themselves can also oscillate and break, removing the mechanism that pulls the throttle closed entirely. In any of these cases, the driver may need to apply the brakes firmly or switch off the ignition to slow the vehicle. Prior repair attempts did not fully resolve the cold-weather cable issue, and a follow-up campaign was issued to address remaining affected vehicles.
On the fuel side, a combination of high altitude, high temperatures, or fuel contamination can cause vapor bubbles to form in the fuel delivery system, leading to rough running or stalling. There is also an electrical concern: a bolt securing the main wiring harness under the fuse panel in the engine compartment can loosen and cause a partial or complete loss of electrical function.
